分级有序多孔磺化碳催化果糖转化制5-羟甲基糠醛

Catalytic fructose dehydration to 5-hydroxymethylfurfural over sulfonated carbons with hierarchically ordered pores

  • 摘要: 采用双模板自组装、炭化、氢氟酸蚀刻和磺化等手段制备了具有分级有序多孔结构的磺化碳(SCHOP),并分别在500、600和700℃考察了炭化温度对分级有序多孔碳微观结构的影响;以催化果糖脱水制备5-羟甲基糠醛(5-HMF)为探针反应,评价了SCHOP的催化效果。结果表明,500℃焙烧所制备的SCHOP具有最高的催化活性。SEM、TEM和N2吸附-脱附表明,所制备的催化剂具有规整的分级有序孔结构,但过高的炭化温度会降低炭材料微观结构的有序性;FT-IR、EDS和-SO3H含量测定表明,通过磺化可在碳基体上有效引入磺酸基,炭化温度过高会降低炭材料的芳香性,不利于磺酸基的引入。130℃下反应20 min,果糖的转化率和5-HMF的收率分别高达96.1%和93.4%,表明SCHOP是一种高效固体酸催化剂。

     

    Abstract: Sulfonated carbons with hierarchically ordered pores (SCHOP) were prepared by means of dual template self-assembly, carbonization, HF etching, and sulfonation. The effect of carbonization temperature on microstructure of the prepared carbons as well as the SCHOPs were surveyed at 500-700℃. Using fructose dehydration to 5-hydroxymethylfurfural as a probe reaction, catalytic performance of SCHOPs was examined. The results show that SCHOP-500 carbonized at 500℃ exhibits the highest catalytic activity. SEM and TEM characterization as well as N2 adsorption desorption show that all of the SCHOPs possess hierarchically ordered macropores and mesopores, but high carbonization temperature damages the regularity of carbon materials slightly. FT-IR, EDS and -SO3H determination confirm that sulfonic acid group could be successfully introduced to carbon materials by sulfonation. However, high carbonization temperature lowers aromaticity of the carbon materials, and as a result leading to low sulfonation degree. Under the catalysis of SCHOP-500, as high as 93.4% of 5-HMF yield with 96.1% fructose conversion rate is achieved after reacting at 130℃ for 20 min, indicating that SCHOP-500 is a highly effective and efficient solid acid catalyst.

     

/

返回文章
返回